-LRB- CNN -RRB- -- Licenses were awarded to 20 medical marijuana dispensaries in Massachusetts , the first in the state after a voter-approved law went into effect in 2013 , state officials announced Friday .

The Massachusetts Department of Health and Human Services said 100 finalists applied for licenses and were judged on how they served the public health , their security and strength of their business plans , as well as their focus on the ability to meet patients ' needs .

`` Health officials designed a rigorous process for vetting applicants , '' said the statement , citing a process that included a selection committee that determined the ability of each applicant to `` meet overall health needs to registered patients while ensuring public safety . ''

The law went into effect January 1 , 2013 , and allows the department to register up to 35 nonprofit registered marijuana dispensaries .

In addition to the 20 approved , eight other applicants were qualified but the proposed locations were rejected , the statement said . Those applicants will be able to reapply in other counties that do not have a licensed dispensary , according to the department .

Patients who have a written certification from a physician for medical marijuana will be registered in an online system , according to the department .

Medical marijuana dispensaries serve clients who suffer ills ranging from cancer to AIDS to chronic pain .

Proponents say the drug 's pain-relieving properties offer an alternative for cancer patients undergoing chemotherapy or radiation treatments .

Eighteen states have either decriminalized or allowed medical marijuana in some fashion . While the state laws have allowed dispensaries to open , they remain illegal under federal law . Fourteen states allow dispensaries , according to the National Conference of State Legislatures .

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Massachusetts grants licenses for 20 medical marijuana dispensaries

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Some 100 finalists applied for licenses

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A voter-approved law allows up to 35 non-profit registered marijuana dispensaries